Work vehicle boom assembly providing improved visability

ABSTRACT

A work vehicle has a boom assembly for a work implement that provides an improved sightline between the cabin and work implement. The boom assembly can be a dual function boom having a wishbone configuration with an elongated body supporting the work implement and at the other end having branch sections extending outwardly at acute angles with open space therebetween. A boom support arch can provide an elevated boom mount on which the boom can pivot about a boom pivot axis at pivots located on the branches of the boom. The boom support arch can have its own pivotal mounting connection to the work vehicle. Actuators, such as hydraulic cylinders, can be coupled to the boom and support arch to independently pivot the boom and the support arch with respect to each other and the work vehicle.

CROSS-REFERENCE TO RELATED APPLICATION(S)

Not applicable.

STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

FIELD OF THE DISCLOSURE

This disclosure relates to work vehicles and booms for work vehicles that support and position implements attached thereto.

BACKGROUND OF THE DISCLOSURE

Work vehicles known as skidders are heavy-duty vehicles used in the forestry industry to gather and clear logs. Cable skidders use a winch line to wrap around and winch the logs together so that the skidder can drag them to the landing area. Grapple skidders have a grapple mounted on a boom at the rear of the vehicle that the vehicle operator controls, using onboard controls and actuation systems, to raise, lower, and rotate the grapple as well as open and close the grapple tongs as needed to clamp around the logs that are to be dragged away by the skidder.

Grapple skidders generally come in one of three types based on the type of boom employed. The booms of grapple skidders are considered single function booms if they have a single degree of freedom, in which the boom pivots about a single axis, typically parallel with the vehicle axles, to raise and lower the grapple above the ground. Dual function booms provide a second degree of freedom. Dual function booms have a boom support pivotally mounted to the vehicle chassis, typically in parallel with the vehicle axles, to which the boom is pivotally connected about a second parallel axis that is raised above the vehicle chassis. Dual function booms give the operator the additional ability to control the reach of the grapple behind the vehicle. Swing booms pivot about a vertical axis so that the boom can swing from one side of the skidder to the other and thereby position the grapple to the sides of the vehicle.

A common concern with work vehicles having boom-mounted work implements, including single function, dual function and swing booms, is the ability of the vehicle operator to see the implement and the work area behind the vehicle, such as in order to clamp the grapple tongs around the logs. As mentioned, the boom and grapple are typically mounted at the rear of the machine such that the operator must look over his shoulder or readjust the seat to even face the grapple. Yet even then, in conventional fixed boom assemblies the boom interferes with, if not almost entirely blocks, the operator's line of sight to the implement. The mounting position and height of the boom and the large, heavy-duty construction required for the boom and boom support components further exacerbate the problem of poor operator visibility to the area being worked. Furthermore, the additional elevated pivot connection often found in dual function booms creates another obstacle in the sightline between the vehicle cabin and the implement.

This disclosure addresses the aforementioned problems.

SUMMARY OF THE DISCLOSURE

An improved boom construction, and work vehicle having an improved boom, is disclosed that affords the vehicle operator a better line of sight to the work tool implement and the area being worked. The boom mounts the implement at one end and has a split end in which two branches angle outwardly away from each other leaving an open space between the branches. The boom is mounted such that the pivotal connection is located at the branches of the boom and the opening extends beyond the pivot axis of the boom. This arrangement creates a window for a sightline between the vehicle and the implement such that the vehicle operator can view the implement and work area behind the vehicle.

In one form, the boom can generally take a generally Y-shaped or wishbone configuration. However, other configurations which include an elongated body and widened end with a window opening are envisioned. The open space between the branches of the boom creates a generally triangular area at least in part forming the window, which can have a greater dimension in the direction of the boom pivot axis than does the elongated body of the boom itself and can extend in the direction of the boom axis closer to the elongated body than the boom pivots.

The wishbone configuration also allows the pivots of the boom to be spaced apart in the dimension of the boom pivot axis greater than the corresponding dimension of the elongated body of the boom. The boom pivots can be lugs in which each lug has a flange segment that is substantially parallel to the boom axis along which the elongated body extends and one more flange segments that are substantially parallel to, and located near, an edge of the associated branch section of the boom.

Moreover, the boom can be of a hollow box construction or in any event define an interior passage extending down the elongated body of the boom to the implement attachment location. Similarly, the boom support can be of a hollow box construction having an interior passage such that a working line (e.g., electrical wires or working fluid plumbing lines) can be routed through the interior passages of the boom support and the boom. The boom or the boom support can also have a bulkhead for coupling shorter working lines together. In this way electrical and plumbing lines can be kept free from entanglement and obstructing the operator's line of sight. The shorter lines are also easier to service and replace.

The boom can also mount a work light to illuminate the implement and work area. For example, the light can be located at an underside of the elongated body of the boom between the boom pivot axis and where the implement is attached. The on-boom light thus further improves the operator's view of the implement and work area, particularly in no or low ambient light conditions.

Thus, in one aspect this disclosure provides a boom assembly for a work vehicle which includes: a boom support providing a boom mount with spaced apart pivots defining a boom pivot axis; a boom having a with an elongated body section extending along a boom axis and first and second branch sections extending from the body section at acute angles on each side of the boom axis defining an open space therebetween, the branch sections having pivots pivotally coupled to the pivots of the boom mount along the boom pivot axis; and a boom actuator including a pair of cylinders coupled to the branch sections of the boom at a side of the boom pivot axis opposite the body section to pivot the boom with respect to the boom support.

Another aspect this disclosure provides in a work vehicle having a boom for a work implement, a boom assembly which includes: a boom support arch providing an elevated boom mount with spaced apart pivots defining a boom pivot axis; a boom having a Y-shaped configuration with an elongated body section extending along a boom axis to a distal end where the work implement is attachable and first and second branch segments extending from the body section at acute angles on each side of the boom axis defining an open space therebetween, the branch segments having pivots pivotally coupled to the pivots of the boom mount along the boom pivot axis; and a boom actuator including a pair of cylinders coupled to the branch sections of the boom at a side of the boom pivot axis opposite the body section of the boom to pivot the boom with respect to the boom support arch.

Yet another aspect of the disclosure provides a work vehicle having a dual function boom assembly for a work implement in which the boom assembly includes: a boom support arch providing an elevated boom mount with spaced apart pivots defining a boom pivot axis, the boom support arch having a pivotal mounting connection to the work vehicle; a boom support actuator including a pair of cylinders to pivot the boom support arch about the pivot connection; a boom having a Y-shaped configuration with an elongated body section extending along a boom axis to a distal end where the work implement is attachable and first and second branch sections extending from the body section at acute angles on each side of the boom axis defining an open space therebetween, the branch sections having pivots pivotally coupled to the pivots of the boom mount along the boom pivot axis; and a boom actuator including a pair of cylinders coupled to the branch sections of the boom at a side of the boom pivot axis opposite the body section of the boom to pivot the boom with respect to the boom support arch.

Still other features of the improved boom will be apparent from the following description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are front and rear perspective views showing a work vehicle in the form of a grapple skidder having an example boom assembly according to this disclosure;

FIG. 3 is rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is an enlarged partial left side view thereof superimposed with operator sightlines shown in dot-dash and dashed lines;

FIGS. 6-10 illustrate the example boom in isolation, shown from the bottom, top, left side, rear and front views, respectively;

FIGS. 11-14 illustrate the example boom assembly mounted on the rear chassis of the work vehicle, shown from the front perspective, left side, top, and rear views, respectively;

FIGS. 15-16 are front and rear views thereof with the example boom assembly in respective fully retracted and horizontal boom positions;

FIGS. 17-20 are partial left side views similar to FIG. 5 albeit showing the boom assembly in different pivotal positions and superimposed with a consistent horizontal sightline in dashed line and operator sightlines shown in dot-dash lines;

FIG. 21 is an enlarged partial perspective view of the pivot connections between the boom and the boom support arch; and

FIG. 22 is a sectional view through line 22-22 of FIG. 21 showing one of the pivot connections between the boom and the boom support arch.

DETAILED DESCRIPTION

The following describes one or more example constructions of a boom assembly 30 and work vehicle 32, as shown in the accompanying figures of the drawings described briefly above. Various modifications to the example construction(s) may be contemplated by one of skill in the art.

FIGS. 11-14 show an example application of the boom assembly 30 incorporated into the work vehicle 32 which powers and controls an implement attachment 34 through a bundle of electric and hydraulic working lines 36. In the example shown in FIGS. 1-5 and described herein, the work vehicle 32 is a skidder and the implement attachment 34 is a grapple. For simplicity a single machine and attachment are described herein as an example application. However, the boom assembly 30 can be utilized with various work vehicles and implements, including with tractors and other agricultural, forestry or construction vehicles with any applicable implement attachment. As such, the terms “work vehicle” and “implement” are not limited to the skidder and grapple described herein.

Turning now to the example embodiment, the skidder 32 generally has an articulating chassis 40 on a front end of which is mounted a cabin 42, engine compartment 44 and front implement 46, shown as a stacking or decking blade, and on a rear end of which is mounted the boom assembly 30 which suspends the grapple 34. The vehicle drive train is configured to couple power from the engine to the front and rear axles 50 to rotate the wheels 52. It should be noted that any type of suitable drive train can be used, including direct drive and final drive systems, with any suitable number of axles, and further that the wheels could drive tracks rather than mount tires as shown. The chassis 40 supports all other electric, pneumatic or hydraulic power subsystems, all engine cooling and exhaust subsystems, all operator controls in the cabin 42 and all vehicle lighting subsystems. For example, the chassis 40 mounts a hydraulic system, including a hydraulic reservoir and pump (not shown), that drives the boom assembly 30 and grapple 34 via hydraulic pressure communicated to the associated actuator components via the working lines 36.

This disclosure pertains to the construction and operation of the boom assembly 30, and in particular to the unique construction of the boom 60, which gives the operator in the cabin 42 a better sightline to the grapple 34 and the work area behind the skidder 32 as well as provides for additional benefits discussed below. Accordingly, the following will describe in detail the boom assembly 30 without also describing the remainder of the skidder 32 or the construction of the grapple 34, which will be generally understood by those of skill in the art of heavy equipment and machinery familiar with existing skidders and grapple attachments, such as commercially available from Deere & Co. of Moline, Ill.

The boom assembly 30 of the example skidder 32 shown in FIGS. 1-5 is a dual function boom assembly, that is, it provides two degrees of freedom in which the grapple 34 can be moved above and beyond the rotation and articulation of the grapple 34 itself. The example boom assembly 30 generally includes the boom 60, a boom support arch 62, a boom actuator 64 and a boom support actuator 66. The actuators 64, 66 for the boom 60 and boom support arch 62 can be any heavy-duty hydraulic cylinders, such as single and double acting telescoping piston cylinders of suitable displacement and stroke length.

As will be described in more detail below, the boom 60 suspends the grapple 34 at a distal end thereof so that the grapple 34 can be maneuvered to a work area behind the skidder 32. The boom support arch 62 is mounted to the chassis 40 at a pivot mount 68 generally at the level of the chassis 40, and the boom 60 is mounted to the boom support arch 62 at an elevated pivot mount 70. From within the cabin 42, the operator controls the height of the grapple 34 primarily by activating the boom actuator 64 to pivot the boom 60 about the boom support arch 62 and controls the reach of the grapple 34 primarily by activating the boom support actuator 66 to pivot the boom support arch 62, and thereby also the boom 60, about the chassis 40. As is known, the operator can further articulate the grapple 34 in position to clamp against the objects, such as logs and felled trees, that are to be dragged away by the skidder 32. The grapple 34 itself can be any suitable conventional grapple mechanism, such as a heavy-duty hydraulic logging grapple having a grapple head 72 and a large pair of opposed grapple tongs 74. The grapple head 72 can include hydraulic cylinders (not shown) for actuating the grapple tongs 74 to open and close. The grapple 34 can mount to the boom 60 by a head joint and hydraulic motor assembly 76, which permits the operator to rotate the grapple 34 up to 360 degrees as needed to properly orient the grapple tongs 74.

Referring to FIGS. 6-10, the boom 60 itself can have a generally wishbone configuration that is symmetric about a central boom axis 80. Specifically, the boom 60 can have an elongated body section 82 extending along the boom axis 80 to the distal end where the grapple 34 mounts. At the opposite end of the body section 82 from the grapple 34, the boom 60 forks into two branch sections 84, which extend outwardly on each side of the boom axis 80. In the example construction, the branch sections 84 have outwardly angled segments 86 that extend at an acute angle to the boom axis 80 and straight segments 88 generally parallel with the boom axis 80.

The example boom 60 has a hollow box construction in which a top panel 90, a bottom panel 92 and several side panels 94 are metal plates that are welded together to form the wishbone configuration. The bottom panel 92 of the boom 60 has a flange 96 at the distal end of the body section 82 for mounting the grapple head joint and motor assembly 76 that suspends the grapple 34. The top panel 90 has a removable cover and access opening 98 for accessing the electric and/or hydraulic working lines 36 to the grapple 34. The bottom panel 92 has an opening located in the body section 82 near the forked end for a work light 100. The bottom panel 92 has additional openings 102, which can have compliant or rigid grommets or other friction and load dampening linings along their peripheries that reduce damage to the lines, to allow access to the interior of the boom 60. The hollow box construction of the boom 60 permits electrical and/or hydraulic working lines 36 to be routed through the interior of the boom 60 rather than along the exterior of the boom 60 where they are susceptible to damage and interfering with the operation of the skidder 32 and grapple 34 or obstructing the operator's view of the grapple 34 and work area.

The branch sections 84 of the boom 60 each have two pivot locations, namely a pair of pivot lugs 104 extending substantially perpendicularly from the bottom panel 92 at the angled segments 96 along a boom pivot axis 106, and a pair of clevises 108 extending substantially perpendicularly from the straight segments 88. The pivot lugs 104 can be formed to have two or more segments at an angle to each other. For example, each pivot lug 104 can have a straight center flange segment 110 that is substantially parallel to the boom axis 80 and has an opening centered on the boom pivot axis 106 that receives a bushing or bearing 112. Each pivot lug 104 can also have front 114 and rear 116 angled end flange segments that extend near and substantially parallel to respective inner and outer edges of the branch sections 84. Aligning the angled end segments 114, 116 with the edges of the branch sections 84 reduces the localized strain at area of attachment of the pivot lugs 104 by better dispersing the strain down the length of the boom 60.

With reference to FIG. 6, a more precise description of the mounting location of the pivot lugs 104 will now be given. As shown, the pivot lugs 104, and in particular the central segments 110 thereof, are located on the angled segments 86 of the branch sections 84 at opposite sides of the boom axis 80 centered on the boom pivot axis 106 at a distance “A”, which is greater than the distance spanning the short dimension of the body section 82. Moreover, the opening of the center segment 110 of the pivot lug 104, which receives the bearing 112 and defines the boom pivot axis 106, is located a distance “B” along the boom axis 80 in the direction away from the grapple mounting side of the boom 60 from the inner periphery 118 of an open space 120 between the branch sections 84 of the boom 60. Thus, the open space 120 begins closer to the grapple end of the boom 60 than the pivot location of the boom 60. Consequently, as will be described in more detail, for a set of pivot angles of the boom 60 about the boom pivot axis 106 above horizontal and the open space 120 provides or contributes to a window for a direct operator sightline from the cabin 42 to the grapple 34.

With reference to FIGS. 11-14, the boom 60 is mounted at an elevated height above the chassis 40 by the boom support arch 62, which can have the horseshoe configuration shown. In this configuration, the boom support arch 62 has a generally straight cross-segment 122 between the upper ends of two upright segments 124 which can toe in slightly from top to bottom. Like the boom 60, the boom support arch 62 has a metal plate, hollow box construction formed of front 126 and rear 128 horseshoe shaped panels with a plurality of side panels 130 welded between the front 126 and rear 128 panels. Also, like the boom 60, the hollow box construction of the boom support arch 62 permits electrical and hydraulic working lines 36 to be routed through the interior of the boom support arch 62 rather than along its exterior where they are susceptible to damage and interfering with the operation of the skidder 32 and grapple 34 or further obstructing the operator's view of the grapple 34 and work area. Also, the upper panel of the cross-segment 122 can have openings 132, which can have grommets or other friction and load dampening linings along their peripheries, to allow passage of the working lines 36 between the interiors of the boom 60 and boom support arch 62. Furthermore, one or more of the side panels 130 can have a removable cover and access opening 134 for a bulkhead manifold (not shown) for connecting together shorter lengths of hydraulic lines 36, which facilitates installation and repair of the lines.

The boom support arch 62 is pivotally connected to the chassis 40 about a boom support pivot axis 136 at the pivot mount 68, and the boom 60 is pivotally connected to the boom support arch 62 about the boom pivot axis 106 at the elevated pivot mount 70. Each pivot mount 68, 70 can be an assembly of mating lug flanges and devises. In the illustrated example, devises 138 are welded to the boom support arch 62 at the cross-segment 122 for pivot mount 70 and at the distal ends of the upright segments 124 for pivot mount 68. Mating lug flanges are welded to the branch sections 84 of the boom 60 at pivot mount 70, as previously described, and also to the chassis 40 at pivot mount 68. Of course, the specific mounting component, lug or clevis, could be interchanged. All four pivots of the pivot mounts 68 and 70 can be operationally the same, and thus only one of the pivot assemblies will be described in detail.

With references to FIGS. 21 and 22, the left side pivot (isolated in FIG. 22) of pivot mount 70 includes the associated pivot lug 104 of the boom 60 and clevis 138 of the boom support arch 62. The mating lug 104 and clevis 138 are joined by a flag pin 140, which can be statically mounted in the clevis 138 along the boom pivot axis 106 so as not to rotate and on which the straight bore lug bearing 112 can rotate. The flag pin 140 can be secured by a split-ended retainer 142 that has an opening 144, which fits into a mating annular groove near an end of the flag pin 140. The retainer 142 can be bolted to the clevis 138 by a bolt 146 inserted through corresponding openings in the retainer 142 and clevis 138. Spacers 148 can be welded to the inside of the clevis 138 and/or to the outside of the pivot lug 104 to reduce play along the boom pivot axis 106. Additional shims or washers 150 can be mounted on the flag pin 140 between the fixed spacers 148 as needed to further shore up the connection and facilitate smooth pivoting action. The flag pin 140 can also have a fitting 152 communicating with internal passages 154 leading to the bearing 112 for applying grease or other lubricant at the pin/bearing interface in situ and without requiring disassembly of the pivot.

Similar lug flange and clevis pivotal connections can be used for the boom 64 and boom support 66 actuators. For example, with reference to FIGS. 11, 12 and 15, a pair of inner pivot lugs 160 and a pair of outer pivot lugs 162 can be welded to the chassis 40, which mate with clevis ends of the cylinder pairs of the associated actuators 64, 66. Additional pivot lugs 164 can be welded to the front panel 126 along the upright segments 124 of the boom support arch 62, which pivotally connect with devises at the piston ends of the cylinder pair for the boom support actuator 66. The piston ends of the cylinder pair for the boom actuator 64 can have rod eyes or trunnions that mate with the devises 108 at the end of the boom 60. Because the devises 108 are mounted at the ends of the widely spaced branch sections 84, the devises 108 can be aligned with the pivot lugs 160 such that the cylinders of the boom actuator 64 can be arranged in parallel to each other on opposite sides of, and parallel with, the boom axis 80. The boom support actuator 66 has a similar parallel cylinder mounting arrangement in which the pivot lugs 162 and 164 are essentially co-planar. This permits the actuators 64, 66 to be pivotally coupled to the boom 60 and boom support arch 62 by straight-bore bushings or plain cylindrical bearings, rather than spherical bearings as would normally be required for out of plane, non-parallel cylinder mounting arrangements. Straight bearings and plain bearings are easier to lubricate, less complex and more durable than spherical bearings, which extends the operational life of the boom assembly 30 between maintenance periods.

Having described the pertinent components of an example grapple skidder 32, the improvements in operator visibility of the grapple and work area that the example construction of the disclosed boom assembly 30 provides will now be described. As mentioned, the example boom assembly 30 is a dual function boom assembly that permits independent pivoting about the boom pivot axis 106 and the boom support pivot axis 136. From within the cabin 42, the operator controls the height of the grapple 34 primarily by activating the boom actuator 64 to pivot the boom 60 about the boom pivot axis 106 and the reach of the grapple 34 primarily by activating the boom support actuator 66 to pivot the boom support arch 62, and thereby also the boom 60, about the boom support pivot axis 136.

FIGS. 15 and 17 illustrate the boom assembly 30 in its home position. For the illustrated example, in the home position, the cylinders of the actuators 64, 66 are fully retracted forward such that the boom support arch 62 is in its furthest counter-clockwise angular position (as viewed from the left side show in FIG. 17), which corresponds to an angle α of approximately 100° with respect to the chassis 40, or horizontal if the chassis 40 is parallel to the horizon. In the home position, the boom 60 is also in its furthest counter-clockwise angular position, which corresponds to an angle β of about 40° from horizontal, or with respect to the chassis 40 if it is not horizontal. Also, in the home position the included angle γ between the intersection of the centerline through the boom support arch 62 and the boom axis 80 is about 60°. FIGS. 18-20 illustrate three of the numerous intermediate positions to which the boom assembly 30 can be pivoted, including the horizontal boom position depicted in FIG. 20. The approximate values of the three angles α, β and γ mentioned above corresponding to the boom assembly 30 positions shown in FIGS. 17-20 are summarized in the table below.

Position α β γ H FIG. 17 100°  39° 61° 15.2″ FIG. 18 92° 20° 73° 14.8″ FIG. 19 76°  6° 68° 13.4″ FIG. 20 63°  0° 63° 11.6″ The above table also provides approximate values of the vertical height “H”, as notated in FIG. 15, of the visibility window created by the boom assembly 30 at the four positions shown in FIGS. 17-20. As noted, the “H” values range from about 15.2″ to about 11.6″ throughout the range of motion depicted in FIGS. 15-20.

It should be noted that the value “H” represents the vertical dimension of the open space above the boom support arch 62 through which an operator inside the cabin 42 can view the grapple 34 without being obstructed by the boom 60. This dimension includes the height of the air space between the top of the boom support arch 62 and the bottom of the boom 60, as in the position shown in FIGS. 16 and 20, as well as any of the open space 120 between the branch sections 84 of the boom 60 which adds to the visibility window when the boom 60 is in a suitable angular position, such as the home position shown in FIGS. 15 and 17. The range of operator sightlines through the visibility window are depicted graphically by the dot-dash lines in FIGS. 17-20. It should also be noted that the dimension “H” does not include the additional visibility window that is present beneath the cross-segment 122 of the boom support arch 62, such as represented by the lower operator sightline (dashed line) in FIG. 5.

As can be seen in FIGS. 15-20, the boom assembly 30 provides a consistent sightline “S” for the operator throughout the range of motion shown in FIGS. 15-20, including from the home position of FIG. 15 to the horizontal boom position of FIG. 20. The sightline “S” is depicted by the horizontal dashed line in FIGS. 17-20 and the crosshair in FIGS. 15 and 16. As shown, the sightline extends from approximately eye-level of a seated operator inside the cabin 42 to the grapple 34. In each position, the sightline “S” is maintained at the same height from a common reference point, such as on the chassis 40 or the ground. This gives the operator not only a direct view of the grapple 34, but also a consistently positioned, centralized window to look through, thereby reducing the frequency and extent to which the operator would be required to crane his neck to view the grapple 34.

As mentioned, additional visibility, particularly toward the ground or lower part of the work area, as shown in FIG. 5, can be gained by angling the sightline downward by the operator simply looking or tilting his head downward. Adjusting the sightline to angle downward from the cabin 42, would be particularly advantageous for viewing the grapple 34 should the boom assembly 30 be extended beyond the FIG. 20 horizontal boom position, such as when the grapple 34 is to be used in a subterranean work area. Thus, even in that case a direct operator sightline (albeit not the same sightline “S”), exists between the cabin 42 and the grapple 34. Such increased visibility throughout the range of motion is useful during operation of the grapple both pick up a load and to monitor the load as it is transported.

It should also be noted that the boom assembly 30 provide benefits in addition to the improved visibility for the operator. For example, the wide pivotal connection of the boom 60 to the support arch 62 allows the boom assembly 30 to better handle torque loading applied to the boom 60 by the grapple 34. In addition, as compared to a corresponding wide pivot full-body boom, the presence of the open space 120 between the branch sections 84 reduces the weight of the boom, thereby allowing for improved energy efficiency and/or more cargo load weight. The wider connections and structures are more efficient and with less weight, and the wider stance increases the operational life of the bushings and pins at the pivots due to the lower torque loads passing through the pins.

The foregoing detailed description describes the subject of this disclosure in one or more examples. A skilled person in the art to which the subject matter of this disclosure pertains will recognize many alternatives, modifications and variations to the described example(s). The scope of the invention is thus defined not by the detailed description, but rather by the following claims. 

What is claimed is:
 1. A boom assembly for a work vehicle, comprising: a boom support providing a boom mount with spaced apart pivots defining a boom pivot axis; a boom having an elongated body section extending along a boom axis and first and second branch sections extending from the body section at acute angles on each side of the boom axis defining an open space therebetween, the branch sections having pivots pivotally coupled to the pivots of the boom mount along the boom pivot axis; and a boom actuator including a pair of cylinders coupled to the branch sections of the boom at a side of the boom pivot axis opposite the body section to pivot the boom with respect to the boom support.
 2. The boom assembly of claim 1, wherein the boom support is an arch providing an elevated platform for the boom mount and having uprights with pivot connections for pivotally coupling to the work vehicle.
 3. The boom assembly of claim 2, further including a boom support actuator including a second pair of cylinders coupled to the boom support for pivoting the boom support with respect to the work vehicle about the pivot connections.
 4. The boom assembly of claim 1, wherein the pivots of the boom are pivot lugs extending away from the boom substantially perpendicularly.
 5. The boom assembly of claim 4, wherein the pivot lugs each include a flange segment that is substantially parallel to the boom axis.
 6. The boom assembly of claim 5, wherein each pivot lug includes a flange segment that is substantially parallel to an edge of the associated branch section of the boom.
 7. The boom assembly of claim 6, wherein each pivot lug includes two flange segments that are substantially parallel to opposite edges of the associated branch section of the boom, one on each side of the flange segment that is substantially parallel to the boom axis.
 8. The boom assembly of claim 7, wherein the two flange segments that are substantially parallel to the edges of the associated branch of the boom are located proximate to the edges of the associated branch section.
 9. The boom assembly of claim 5, wherein the pivots of the boom support are devises defining recesses in which are disposed the flange segments that are substantially parallel to the boom axis.
 10. The boom assembly of claim 1, wherein the boom in part has a hollow interior extending along the body section of the boom to an implement attachment location at a distal end of the body section of the boom.
 11. The boom assembly of claim 10, wherein boom support in part has a hollow interior such that a working line can be routed through the interior of the boom support and the boom.
 12. The boom assembly of claim 11, wherein at least one of the boom support and the boom has a bulkhead for coupling working lines.
 13. The boom assembly of claim 1, wherein the boom mounts a work light located at an underside of the body section of the boom between the boom pivot axis and an implement attachment location at a distal end of the body section.
 14. The boom assembly of claim 1, wherein at least in part the open space between the branch sections of the boom has a greater dimension in the direction of the boom pivot axis than the body section of the boom and extends in the direction of the boom axis closer to the body section of the boom than the boom pivots.
 15. In a work vehicle having a boom for a work implement, a boom assembly comprising: a boom support arch providing an elevated boom mount with spaced apart pivots defining a boom pivot axis; a boom having a wishbone configuration with an elongated body section extending along a boom axis to a distal end where the work implement is attachable and first and second branch segments extending from the body section at acute angles on each side of the boom axis defining an open space therebetween, the branch segments having pivots pivotally coupled to the pivots of the boom mount along the boom pivot axis; and a boom actuator including a pair of cylinders coupled to the branch sections of the boom at a side of the boom pivot axis opposite the body section of the boom to pivot the boom with respect to the boom support arch.
 16. The boom assembly of claim 1, further including a boom support actuator including a second pair of cylinders, wherein the boom support arch includes pivot connections pivotally coupled to the work vehicle, and wherein the second pair of cylinders pivot the boom support arch about the pivot connections.
 17. The boom assembly of claim 15, wherein the pivots of the boom are pivot lugs, and wherein each pivot lug includes a flange segment that is substantially parallel to the boom axis and a flange segment that is substantially parallel to an edge of the associated branch section of the boom.
 18. The boom assembly of claim 17, wherein the flange segment that is substantially parallel to the edge of the branch section of the boom is located proximate to the edge of the associated branch section.
 19. A work vehicle having a dual function boom assembly for a work implement, the boom assembly comprising: a boom support arch providing an elevated boom mount with spaced apart pivots defining a boom pivot axis, the boom support arch having a pivotal mounting connection to the work vehicle; a boom support actuator including a pair of cylinders to pivot the boom support arch about the pivot connection; a boom having a wishbone configuration with an elongated body section extending along a boom axis to a distal end where the work implement is attachable and first and second branch sections extending from the body section at acute angles on each side of the boom axis defining an open space therebetween, the branch sections having pivots pivotally coupled to the pivots of the boom mount along the boom pivot axis; and a boom actuator including a pair of cylinders coupled to the branch sections of the boom at a side of the boom pivot axis opposite the body section of the boom to pivot the boom with respect to the boom support arch.
 20. The work vehicle of claim 19, wherein the pivots of the boom are pivot lugs, and wherein each pivot lug includes a flange segment that is substantially parallel to the boom axis and a flange segment that is substantially parallel to an edge of the associated branch section of the boom. 